1. Field of the Invention
The present invention relates generally to flexible connections and more particularly to an externally removable bushing that provides a flexible connection to components located within a switchgear.
2. Description of the Related Art
Switchgear for electrical power distribution systems commonly include enclosures defining contained environment desirable for circuit-interrupting functions of the enclosed components. In order to connect the enclosed components to external power cables, a bushing is utilized to provide a conductor through the sealed enclosure of the switchgear and to insulate the conductor from the enclosure. The bushing typically includes provisions for assembly with separable connectors which interface between the bushing and the power cables. The external portions of the bushing are subject to damage which may render the bushing unusable, requiring replacement of the bushing. This requires disconnection of the bushing from the enclosed components. If this disconnection of the bushing requires opening of the enclosure, the replacement of the bushing is not only time-consuming and difficult to perform in confined spaces, the design of the switchgear enclosure is also complicated thereby since opening features must be incorporated.
U.S. Pat. Nos. 4,767,351 and 5,904,577 illustrate arrangements that provide an externally-separable bushing such that connection and disconnection to enclosed components may be accomplished external to the enclosure and not requiring opening of the enclosure. In U.S. Pat. No. 4,767,351, the conductor of that bushing arrangement includes a cylindrical rod which is permanently and rigidly attached to the enclosed component and a sleeve with annular passage that receives the rod. The bushing also includes provisions for threadably connecting the two conductor parts. Thus, the bushing is removed by unthreading of the bushing from the cylindrical conductor such that the remainder of the bushing may be removed. This arrangement also requires provisions for sealing the junction of the two conductor parts.
While the prior art arrangements may be useful to provide connections to enclosed electrical components, it is always desirable to provide simplified manufacture and structure.